Improvement in valve-gears for direct-acting engines



UNITED STATES PATENT OFFICE,

ADAM SA. CAMERON, OF NEW YORK, N. Y.

IMPROVEMENT IN VALVE-GEARS FOii DIRECT-ACTING ENGINES.

A Specification forming part of Letters Patent No. 112,015, dated February 2l, 1871.

Fn "1J, whom it 'may concern:

Be it known that I, ADAM S. CAMERON, of the city, county, and State of New York, have invented a new and Improved Valve-Gear for Direct-Acting Engines; and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, referencebein g had to the accompanying drawing, forming part of this specification, in which drawing* Figure 1 represents a sectional' side view of my invention. Figs. 2, 3, and 4 represent modifications of the mechanism illustrated in Fig. 1.

Similar letters indicate corresponding parts.

This invention relates to a direetfaeting engine in which the valve o'f the auxiliary' or main steam-cylinder is actuated by means of a rod secured to the piston ofthe pumping-cylinder and extending alongside of the steam-cylinder, or vice versa, in such a manner that the steam-cylinder and the pumping-cylinder can be placed as close together as may be desired, and at the same time a positive motion is imparted to the steam-valve.

This invention also relates to the arrangement of steam-chambers in the heads of the steam-cylinder, said heads being provided with seats f or valves, which are situated in the steam-chambers, and from which extend arms in the interior of the cylinder in such a' manner that, whenever the piston approaches the end of its stroke, one of said valves is opened, and the steam admitted to the cylinder serves to cushion the piston.

In carrying out this invention I use, by preference, a mechanism such as shown in Fig. 1; but it is obvious that this mechanism may undergo various modifications-such, for instance, as I have shown in Figs. 2, 3, and 4.

In the drawing, the letter A designates the steam-cylinder of a direct-acting engine, which is provided with a piston, B, connected by means of a rod, C, with the piston D of the pumping or blowing cylinder E. The diameter or bore of this last-named cylinder is usually much greater than that of the stean1-cyl inder, so that a rod, F, secured to the piston D, can be made to extend alongside of the steam-cylinder. To this rod I secure one end of a iiexible band, G, of metal-or other suitable material, and this band is carried round a drum, H, and fastened at its other end to the circumference thereof. With the drum H is connected a cog-wheel, I, which gears in a toothed rack, J, and a rod, K, extends from this rack to a sleeve, a, which is fitted on a hand-screw, L. The rod K is made in sections, which are united by a screw-coupling, b, so that it (the rod) can be lengthened or short ened, as may be desired; and the connection between said rod and the sleeve a is effected by'a pivot, c, so as to allow the same to'ae commodate itself to the varying positions ot' the sleeve, said sleeve being attached to. the screw, so that it turns freely thereon without being permitted to move in the direction of its axis. The screw L is tapped into the head d of the spindle c, from which extends a toe, intendedl to impart motion to the valve of tlie auxiliary cylinder M, the piston of this auxiliary cylinderbeing connected by a rod, f, to the main valve.

To the bottom end of the toothed rack J is attached a weight, N, which has a tendency to turn the drum H in the direction of arrow 1, (marked thereon in-Fig. 1,) and abracket, g, which projects over the rear edge of said rack, prevents the same from getting out of gear with the cog-wheel I. This bracket, being made to swing on the axis of the drum H, accommodates itself to the angle of the rack J.

When the piston D moves in the direction of the arrow 2, Fig. 1, the rack J is carried down by its weight N, and the screw L turns down, causing the auxiliary valve to move and to change the main valve to admit steam at the outer end of the steam-cylinder.

When the piston D is moved in the direc` tion opposite to arrow 2 the band G is unwound from the band H, and the 'said drum is turned in the opposite direction to the arrow 1. The rack J is raised and the screw L is swung up, causing the auxiliary valve to move so'as to admit steam at the inner end of the steam-cylinder.

By turning the screw L in or out the distance between the pivot c and the head d of Y the valve-spindle can be shortened or lengthened, and the time when the steam is changed in the auxiliary and main cylinders can be ne. 

